1. Field of the Invention
The present invention relates to a supporting structure, more particularly to an elevating structure having tension adjusting mechanism. The present invention further provides to a tension adjusting mechanism used in an elevating structure, wherein tension of a linking device provided transversally and pivotally to a retractable connecting unit can be properly adjusted via changing distance.
2. Description of Related Art
A flat panel monitor, e.g. a LCD monitor, a LCD TV or a plasma TV, has advantages of light in weight, thin in thickness, and no radiation. Therefore, most of CRT TVs are replaced. When viewing a LCD or a plasma TV, there is a viewing limitation angle, at least one structure of rotation shaft is provided at the bottom seat of the monitor, so the monitor is provided with a function of angle adjusting relative to the bottom seat.
But such art can not allow the flat panel monitor move both upwardly/downwardly and forwardly/backwardly. An auxiliary connecting unit disposed in parallel is therefore invented, e.g. end sections of two connecting rods are respectively connected to a main hinge provided on a top end of a connecting unit and a base hinge provided on a bottom end of the connecting unit. The connecting unit, the auxiliary connecting unit, the main hinge and the base hinge are defined as a linkage mechanism, and the auxiliary connecting unit is served to convert the rotation movement of the connecting unit relative to the bottom seat into a tiling movement of the monitor main body. In other words, when the height of the monitor main body is adjusted, the original angle of the monitor main body is kept the same during the adjustment.
The applicant of the present invention has been devoting himself to break through the market of supporting structure for monitors in which the linkage mechanism is taken by providing a novel linking device. Referring to the U.S. patent application Ser. No. 11/896,930, “ELEVATION-ADJUSTABLE SUPPORT STRUCTURE”, wherein a linking device of the supporting structure is provided by a bottom shaft wheel and a top shaft wheel respectively being provided between a bottom end and a top end of one lateral side of the connecting unit and between a bottom supporting rack and a top supporting rack, and respectively and pivotally connecting to a bottom pivotal shaft device and a top pivotal shaft device, and a flexible band is provided between the top and the bottom shaft wheels; the linking device is served to convert the circular rotation of the connecting unit into rotations of the two top supporting racks for compensating displacements, so the angles of the two top supporting racks are remained the same, so when the supporting structure is applied on an object to be supported, e.g. a flat panel monitor, the original angle of the object is remained the same while the height thereof is being adjusted.
In the above mentioned art, the top shaft wheel and the bottom shaft wheel are linked via a flexible band, if the tension between the top and the bottom shaft wheels and the flexible band is not strong enough, a lose status may be generated and an anticipating linking result may not be obtained.